If you’ve lived in North Texas for more than a few years, you probably have at least one crepe myrtle in your yard. Maybe several. They’re everywhere — and for good reason. They bloom like crazy, they handle brutal summers, and they mostly just… do their thing without asking for much.
So when you walk outside one morning and notice white spots spreading across the bark, it gets your attention. Something’s not right.
Those white spots are crepe myrtle bark scale. And here’s the thing — it’s not going away on its own. But it is very treatable if you understand what you’re dealing with and when to act. That’s what this guide is for.
What Are the White Spots on Crepe Myrtle Bark?
Those white spots on crepe myrtle bark? They’re not mold. They’re not paint. They’re not some weird fungus your tree picked up.
They’re insects. Tiny ones, hiding under a white, felt-like coating they build around themselves. The colonies cluster along branches, limbs, and trunk crevices — basically anywhere the bark has texture for them to tuck into.
Here’s a quick test: press on one of those white spots. If you see a pink or lavender smear, that’s the insect itself. That’s your confirmation.
White spots on crape myrtle trees usually become noticeable in late spring and get worse through summer, especially on the smooth bark sections crepe myrtles are known for. By the time most people notice them, the insects have been feeding for a while.
What Is Crepe Myrtle Bark Scale (CMBS)?
Crepe myrtle bark scale is exactly what it sounds like — a scale insect that targets crepe myrtles. Specifically, it’s Acanthococcus lagerstroemiae, a non-native pest that was first identified in Texas in 2004. It’s been spreading across the state ever since.
Here’s how the life cycle works:
- Eggs hatch beneath the white, waxy covering on bark
- Crawlers (tiny nymphs) emerge and move to new feeding sites along branches and limbs
- Adults settle in, produce the white stuff you see, and feed on sap
- Females produce the next generation — and the whole cycle repeats, often multiple times per season
So the white spots on crepe myrtle bark aren’t just cosmetic. They’re a protective shell. Underneath it, these insects are quietly draining nutrients from your tree, one sap meal at a time.
Why Black Sooty Mold Appears After White Spots
OK, this is where things get a little gross — and a lot more obvious.
As bark scale insects feed on sap, they excrete a sticky substance called honeydew. (Nature’s worst-named byproduct.) That honeydew coats the bark, the branches, and everything underneath the tree — your driveway, your patio furniture, your car if it’s parked too close.
Then a black fungus called sooty mold shows up and colonizes the honeydew. And suddenly your tree looks like it’s been dipped in charcoal.
The progression goes like this:
- Bark scale attaches → white spots appear on bark
- Insects feed on sap → honeydew drips onto surfaces below
- Sooty mold grows on honeydew → bark and surrounding areas turn black
Here’s what’s important to understand: the sooty mold itself doesn’t directly damage the tree. It’s feeding on the honeydew, not the plant tissue. But it blocks sunlight from reaching bark and leaves, which weakens the tree over time. And it makes your crepe myrtle look like it’s given up on life.
How Serious Is Crepe Myrtle Bark Scale Damage?
Let’s answer the big question first: crepe myrtle bark scale probably won’t kill your tree.
But “won’t kill it” and “won’t hurt it” are two very different sentences.
Untreated crape myrtle bark scale can lead to:
- Reduced blooming — fewer flowers, thinner canopy
- Branch dieback on heavily infested limbs
- Increased stress that makes the tree vulnerable to other problems
- Cosmetic damage from sooty mold that can persist for seasons
A healthy, mature crepe myrtle can handle a light infestation. But here’s the part people miss — bark scale compounds. It doesn’t plateau. Left unchecked over two or three seasons, the tree gets weaker, the infestation gets denser, and recovery takes significantly longer.
How to Treat Crepe Myrtle Bark Scale
Treatment depends entirely on how far things have progressed. Let’s break it into two scenarios.
Light Infestations — Early Action
If you’re catching this early — scattered white spots, minimal sooty mold — start here:
- Wash the bark with a soft brush and a mild dish soap and water solution to physically remove scale and honeydew
- Encourage natural predators — lady beetles and lacewings feed on crawlers and are a legitimate form of natural treatment
- Prune and thin overcrowded branches to improve airflow (this is where a professional tree trimming service makes a real difference)
Early action won’t eliminate an established colony, but it can significantly slow the spread and reduce the need for chemical intervention.
Heavy Infestations — Systemic Treatments
When bark scale has spread across multiple limbs and sooty mold is everywhere, you’re past the soap-and-water stage. A systemic insecticide is usually necessary.
The most effective approach:
- Soil-applied systemic treatments containing imidacloprid or dinotefuran, applied at the base of the tree so the product absorbs through the roots
- The insecticide kills crepe myrtle bark scale from the inside out — as the insects feed on treated sap, they die
- Timing is critical — systemic treatments work best when the tree is actively taking up water, typically spring through early summer in Texas
This is where knowing how to treat crepe myrtle bark scale correctly — right product, right timing, right method — separates real results from wasted effort and money.
Why Timing Matters in Texas
While national guides might give broad dates, the North Texas ‘Wake Up’ usually hits in late April. In Plano and Allen, our soil warms up quickly, meaning the systemic uptake window is narrow. If you wait until the July heatwave to treat, the tree is already too stressed to pull the medicine up to the branches. That wide window means:
- Treating too early (before crawlers emerge) reduces effectiveness
- Treating too late (after adults have settled in) means you’re fighting uphill
The best time to treat bark scale on crepe myrtle in Texas is late April through June — when crawlers are most active and systemic uptake is strongest.
Why Bark Scale Is a Growing Problem in DFW
In high-density communities like Stonebridge Ranch in McKinney or Phillips Creek Ranch in Frisco, crepe myrtles are the ‘default’ landscape tree. Because these trees are planted house-after-house, the wind-carried crawlers can jump from your neighbor’s yard to yours in a single afternoon. A few reasons why:
- Crepe myrtles are everywhere. They’re the default landscape tree across Collin County and nearby areas. That gives bark scale an endless supply of hosts — it’s basically an all-you-can-eat buffet that stretches across every subdivision.
- Mild winters. Our winters rarely get cold enough, for long enough, to meaningfully knock back scale populations.
- Lack of awareness. Most homeowners don’t recognize the white spots until black sooty mold has already taken over — by which point the infestation is well-established and harder to treat.
The uncomfortable truth: if your neighbor’s crepe myrtles have bark scale, yours are at risk. Crawlers travel by wind.
Common Mistakes Homeowners Make With Bark Scale
We’ve seen it across Woodbridge in Wylie and Starwood in Frisco: homeowners try to pressure wash the black sooty mold off. Not only does this damage the tree’s sensitive bark, but it doesn’t touch the insects hiding deep in the crevices. You’re essentially giving the bugs a bath without stopping the source.
- Ignoring the white spots: Many assume these are cosmetic or harmless, allowing the infestation to build for seasons.
- Pressure washing the bark: This damages the tree’s smooth outer layer without actually addressing the insects protected underneath.
- Treating at the wrong time: Applying products too early (before crawlers emerge) or too late (after adults have settled in) leads to wasted money and effort.
- Over-pruning: Attempting to “cut away” the problem often results in removing too many limbs, which just stresses the tree further and stunts its recovery.
How to Prevent Crepe Myrtle Bark Scale From Returning
There’s no single magic step here. Prevention is really about keeping your trees healthy and watching closely:
- Inspect bark regularly — especially in spring. Check trunk crevices and branch joints for early white spots on crape myrtle bark before they spread.
- Maintain tree health through proper fertilization and watering so your tree can withstand and recover from infestations faster
- Keep canopies open with regular pruning to improve airflow and reduce the humid, sheltered conditions bark scale prefers
- Watch neighboring trees — bark scale spreads between properties via wind-carried crawlers
- Schedule annual tree care services so professionals can catch early signs long before you’d ever notice them yourself
Consistent monitoring is the closest thing to a guarantee — and it makes crepe myrtle bark scale treatment far simpler and cheaper when it is needed.
When to Call a Professional
Light infestations? You can handle those with careful washing and monitoring. But call in local pest control experts when:
- White spots have spread across multiple limbs and trunk sections
- Black sooty mold is visible on bark, leaves, or surfaces beneath the tree
- You’ve tried treating it yourself and it’s not improving after a full season
- You have multiple crepe myrtles and the infestation is jumping between them
- You’re unsure about the right insecticide, dosage, or application timing
CitiTurf serves homeowners in Collin County and nearby areas with targeted crepe myrtle bark scale treatment programs built around our North Texas climate and seasonal timing. We know when crawlers emerge here, what products work in our soil conditions, and how to eliminate the problem without wiping out the beneficial insects your yard actually needs.
